TEMPERATURE REGIME OF STAMPING TOOLS IN LIQUID STAMPING,

An investigation was made of the effect of the principal technological parameters of the process unit pressure, die-heating temperature prior to the filling of die with molten metal and the weight of the blank itself on the temperature regime of the die assembly during the die casting of steel blanks. The die assembly was made of 3Kh2V8 steel and heat-treated to a hardness of HRC 44-46. Soot from an oil flame was used as the lubricant. Molten metal was poured into the die at 1580-1600C the pressure was 0-70 kgsq mm, the die was preheated to 340-360C prior to the casting of solid-metal cylinders and 250-300C prior to the casting of cupped blanks. The temperature regime of the die assembly during molten metal forging was measured with the aid of chromel-alumel thermocouples and recorded on a MPO-2 oscillograph. The experimental findings thus obtained warrant the following conclusions 1 The principal process parameters pressure, heating temperature of die assembly prior to filling with molten metal and the weight of the forged blank exert a very considerable effect on the temperature regime of operation of the die assembly. 2 During the pressure-die casting of steel blanks the surface layers of the die assembly, consisting of a material with a thermal conductivity of 0.07-0.08 calcm-sec-deg of the 3Kh2V8 steel type become heated to high temperatures as high as 800-850C for dies and 950-1050C for punches during cupping. 3 The zone of propagation of high temperatures over the cross sectional area of the die assembly during one cycle does not exceed 4-5 mm.